Device for preparing and ejecting a chemically reacting mixture

Abstract

A device for preparation of a chemically reacting mixture, and for ejecting the mixture into a mold includes a pair of slides having transverse through openings capable of being mismatched upon relative reciprocation, oscillation and/or vibration of the slides for dynamically setting the mixing pressure.

What is claimed is: 
     
       1. A device for preparing a chemically reacting mixture, and for ejecting the mixture into a mold, the mixture comprising at least two components, in particular a mixture of isocyanate and a polyol that reacts completely to form polyurethane, the device comprising a mixing head having an outwardly open bore, a reciprocable ram coupled to said head, said ram having an ejector rod axially movable in said bore for ejecting the mixture therefrom when in an extended position, said rod defining with said bore a mixing chamber in a retracted position of said rod, said head having inlet passages for inletting the respective components into said chamber for preparing the mixture, said mixing head having guide passage means extending perpendicular to the axis of said bore and being positioned downstream of said rod from said retracted position thereof for delimiting said chamber, a pair of slides having through openings of a size equal to that of said bore, said slides being at least reciprocable in said guide passage means relative to one another between a mixture ejecting position and mixture preparation positions, means for at least reciprocating said slides at a predetermined frequency and/or amplitude and phase shift in accordance with a predetermined mixing pressure required for the mixture, said openings of said slides being coaxial with said bore in said mixture ejecting position to permit said rod to extend therethrough, and said openings of said slides in said mixture preparation positions being out of alignment with said bore for dynamically setting the mixing pressure required for the mixture. 
     
     
       2. The device according to claim 1, wherein said slides comprise telescoping cylindrical bodies having a common axis. 
     
     
       3. The device according to claim 2, wherein said cylindrical bodies are oscillatable relative to one another about said axis thereof, and said means further oscillating said bodies between said ejecting position and said preparation positions. 
     
     
       4. A device for preparing a chemically reacting mixture, and for ejecting the mixture into a mold, the mixture comprising at least two components, in particular a mixture of isocyanate and a polyol that reacts completely to form polyurethane, the device comprising a mixing head having an outwardly open bore, a reciprocable ram coupled to said head, said ram having an ejector rod axially movable in said bore for ejecting the mixture therefrom when in an extended position, said rod defining with said bore a mixing chamber in a retracted position of said rod, said head having inlet passages for inletting the respective components into said chamber for preparing the mixture, said mixing head having guide passage means extending perpendicular to the axis of said bore and being positioned downstream of said rod from said retracted position thereof for delimiting said chamber, a pair of cylindrical bodies having a common axis and having transverse openings of a size equal to that of said bore, said cylindrical bodies being oscillatable in said guide passage means relative to one another about said axis between a mixture ejecting position and mixture preparation positions, means for oscillating said cylindrical bodies at a predetermined frequency and/or amplitude and phase shift in accordance with a predetermined chamber pressure required for the mixture, said openings of said cylindrical bodies being coaxial with said bore in said mixture ejecting position to permit said rod to extend therethrough, and said openings of said cylindrical bodies in said mixture preparation positions being out of alignment with said bore for dynamically setting the mixing pressure required for the mixture. 
     
     
       5. The device according to claim 4, wherein the axes of said transverse openings intersect said common axis. 
     
     
       6. The device according to claim 4, wherein the axes of said transverse openings are spaced from said common axis. 
     
     
       7. The device according to claim 1, wherein a pressure sensor is provided at said chamber for sensing the predetermined pressure thereof. 
     
     
       8. The device according to claim 4, wherein a pressure sensor is provided at said chamber for sensing the predetermined pressure thereof. 
     
     
       9. The device according to claim 1, wherein said mixing head is of ceramic material at least at said bore and at said guide passage means. 
     
     
       10. The device according to claim 4, wherein said mixing head is of ceramic material at least at said bore and at said guide passage means.